Texas Instruments Inc's second-quarter profit beat Wall Street expectations but the company warned that its third-quarter revenue would be weaker than usual for this time of year as customers are cautious due to global economic uncertainties.

Shares of TI, which makes chips for a wide range of products such as cellphones and industrial equipment, fell 1 percent in extended trade after it said Monday that orders weakened in June and that its backlog for shipments due in September is also lighter than expected.

Company executives said TI's customers and distributors are "increasingly cautious in placing new orders" because of the global economic environment even though they have low stockpiles of chips.

Analysts said that the slowdown was not surprising as TI is the latest in a long line of chip companies including Intel Corp and Qualcomm Inc to lower financial targets this quarter.

Because TI's customers are seeing lethargic demand from consumers and corporations, they are not ordering very far in advance, Williams Financial analyst Cody Acree said.

"End demand is not strong enough that anybody's afraid of losing out on market share if they don't carry inventory, so the entire manufacturing food chain is relying on very short delivery times," Acree said.

Bernstein analyst Stacy Rasgon said TI is perhaps being a little cautious about September itself since it said that "order patterns for July and August (were) fairly normal."

TI forecast third quarter revenue of $3.21 billion to $3.47 billion, implying a midpoint that is flat with its second quarter revenue. This compares with TI's 5-year average for third quarter sequential growth of 6 percent.

Chief Financial Officer Kevin said it was not clear whether customers were anticipating a slowdown in their own business or taking advantage of TI's ability to deliver chips relatively quickly because it has high inventory levels.

"It's a little different to draw a concrete conclusion but what we do know is that it's unusual," March told Reuters.

"As we look at our customers our opinion is that their inventories are very lean. That tells us that if in fact we've normal seasonal demand, it's a good thing we've built a lot of inventory," he said.

TI reported earnings of $446 million, or 38 cents per share, down from $672 million, or 56 cents per share, in the year-ago quarter. Excluding certain items, it earned 44 cents per share, above Wall Street expectations for 41 cents according to Thomson Reuters I/B/E/S.

Revenue fell to $3.34 billion from $3.46 billion, compared with analysts' average expectation for $3.35 billion according to Thomson Reuters I/B/E/S.

TI shares fell to $26.60 after closing at $26.82 on Nasdaq. The stock had already fallen about 16 percent since the company's last quarterly report on April 23 as investors worried about slowing chip demand.

(Additional reporting by Noel Randewich in San Francisco; Editing by Richard Chang)